Max wrote:Great demos guys! With enough power, I don't see why a full-sized couldn't fly with one motor of each pair being out. Depending on how the yaw balances out I suppose. Can it fly with both motors on one arm out, though?

Steve, how are you driving the extra 4 motors? Parallel pairs from onboard motor drivers, or you have extra ESCs and all that?

Thanks,-Max

Well with both motors on one arm out it is the same as a quad with one out. I could show you a number of video's in testruns for Srinath that all failed. Only one attempt with heavy code changes did stay in the air for a couple of seconds .We have been trying to get the 'quad' or in this config the x8 to get it yawing so fast the thrust loss would be compensated. Well, it could work on a small and cheating way with some balance shift, but practically.. no (well, I couldn't anyway).

@Steve, that is a great idea for getting props close together. A couple of years ago I did see an attempt from Hacker motors in the time that brushless was not that powerful to stack two motors with one motor having a hollow shaft, where the bottom motor shaft was running through.With pancake motors it could be done. Only the bearings must be very tough because the stacked props could create quite a nasty shake.

About 10 years ago a friend took 2 AXI motors, one with a hollow shaft and made a really nice motor with the props contra rotating. We put it on a model simular the Convair XFY Pogo and were able to take off and land without any problems on the tail. The lack of torque made it pretty easy to do and didn't have to have huge surface deflections to get the job done. Spektrum has a new set of receivers with stabilization that I want to go back and try and fly it again but I unfortunately gave the motor away.

The large pancake motors that are made to have a slipring in the middle should be good candidates but would have to be rewound.

Max,

I didn't want to have to add another four motor drivers so I just put them in parallel. Not very efficient but it flew fine. It weighs close to 70 grams with battery so when all four props were off it was struggling but controllable. I pulled off each prop one at a time and it just got a little weaker each time. No control problems at all and it was just our normal Quatos.